Inflatable flexible structures are old and their use has been proposed for various purposes. For example, flexible shelters have been made substantially airtight and adapted to be maintained in erected state by the constant injection of air somewhat above atmospheric pressure. Such constructions have generally been used for large enclosures such as those employed for tennis courts and other similar areas. These are relatively expensive to construct and to maintain and therefore have enjoyed somewhat limited use.
Flexible sheet shelters employing rigid supporting ribs or similar mechanical supports are generally quite expensive, heavy to transport and are quite complicated to construct and erect.
Efforts have been made to construct enclosures by employing flexible tubes properly shaped to constitute a supporting frame when inflated but insofar as this inventor is aware none of such prior structures are capable of being manufactured as simply and as economically as can the invention here disclosed. One type of such prior device has employed separate inflatable tubular frames which are first inflated and thereafter employed as a support for a separately applied skin. Another form has employed a unitary and composite frame and skin construction.
Prior to this invention insofar as this applicant is aware, it has been necessary with both forms to connect two, three or more tubular rib or frame sections together at the locations where the frame sections join or cross each other in order that the air space inside the tubular frame sections may interconnect with each other. In other words connections have been employed which though flexible are necessarily airtight and otherwise are like the connections employed for connecting pipes by means of T-connectors, cross connectors or other more complex connectors for effecting intercommunication between two or more pipes or tubes which intersect, cross, or otherwise come together.
Inflatable flexible tubular connections similar to the pipe connections above described are complicated and expensive to produce especially in view of the necessity to effect such intercommunication in a completely airtight manner.